Positive electrode active material, non-aqueous electrolyte secondary battery and method for producing positive electrode active material

Abstract

A non-aqueous electrolyte secondary battery employing a positive electrode active material containing a compound represented by the general formula Li x M y PO 4 , where 0<x≦2 and 0.8≦y≦1.2, with M containing a 3d transition metal, where Li x M y PO 4 encompasses that with the grain size not larger than 10 μm. The non-aqueous electrolyte secondary battery has superior cyclic characteristics and a high capacity.

1. A method for producing a positive electrode active material comprising: a mixing step of mixing a starting materials for synthesis of a compound represented by the general formula Li x M y PO 4 , where 0<x≦2 and 0.8≦y≦1.2, with M containing a 3d transition metal; and a sintering step of sintering and reacting said precursor obtained in said mixing step; wherein, in said sintering step, said precursor is sintered at a temperature not lower than 400° C. and not higher than 700° C. 
     
     
       2. The method for producing a positive electrode active material according to  claim 1  wherein, in said sintering step, said precursor is sintered at a temperature not lower than 400° C. and not higher than 600° C. 
     
     
       3. The method for producing a positive electrode active material according to  claim 1  wherein said Li x M y PO 4  is LiFePO 4 .